735
FNCA52 TJSJ 180847
FWFSJU
FIRE WEATHER PLANNING FORECAST FOR PUERTO RICO
NATIONAL WEATHER SERVICE SAN JUAN PR
447 AM AST SAT JUL 18 2026
DISCUSSION
ELEVATED FIRE WEATHER CONDITIONS WILL PERSIST TODAY ACROSS PORTIONS
OF PUERTO RICO, PARTICULARLY ALONG THE SOUTHERN COASTAL PLAINS AND
ADJACENT LOWER ELEVATIONS. RELATIVE HUMIDITY VALUES ARE EXPECTED TO
FALL INTO THE UPPER 40S TO LOWER 50S THIS AFTERNOON, WHILE BREEZY
EASTERLY WINDS OF 15 TO 20 MPH, WITH HIGHER GUSTS, WILL CONTINUE TO
SUPPORT FAVORABLE CONDITIONS FOR RAPID FIRE SPREAD.
CRITICALLY DRY FUELS REMAIN IN PLACE, WITH KBDI VALUES EXCEEDING 700
ACROSS MUCH OF PUERTO RICO. ALTHOUGH ISOLATED AFTERNOON SHOWERS MAY
DEVELOP OVER WESTERN PUERTO RICO, RAINFALL COVERAGE AND AMOUNTS WILL
BE INSUFFICIENT TO PROVIDE MEANINGFUL RELIEF TO THE ONGOING DRY
CONDITIONS. THEREFORE, ELEVATED FIRE WEATHER CONDITIONS WILL
CONTINUE TODAY, WHERE A FIRE DANGER STATEMENT REMAINS IN EFFECT.
PRZ014-182015-
SOUTHEAST COASTAL PLAINS-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 10
TEMP (24H TREND) 92 (+1) 75 (-2) 92
RH % (24H TREND) 46 (-5) 84 (+3) 49
WIND 20FT/EARLY(MPH) E 16 G23 E 13 E 14 G22
WIND 20FT/LATE(MPH) E 16 G24 NE 10 E 17 G26
MIXING HGT(FT-AGL/MSL)5310 5290
TRANSPORT WND (MPH) E 18 E 17
VENT RATE (KT-FT) 84960 79350
DISPERSION 5 5
DSI 6 3 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ015-182015-
SOUTHERN HILLS-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 10
TEMP (24H TREND) 90 (+4) 70 (-4) 90
RH % (24H TREND) 54 (-7) 95 (+5) 54
WIND 20FT/EARLY(MPH) E 13 E 12 E 14
WIND 20FT/LATE(MPH) E 14 E 12 E 14
MIXING HGT(FT-AGL/MSL)5760 6060
TRANSPORT WND (MPH) E 15 E 16
VENT RATE (KT-FT) 74880 84840
DISPERSION 5 5
DSI 6 3 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ016-182015-
NORTH COASTAL PLAINS-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 30 20
TEMP (24H TREND) 91 (+1) 73 (-4) 90
RH % (24H TREND) 58 (-4) 97 (+7) 58
WIND 20FT/EARLY(MPH) E 16 E 18 E 16
WIND 20FT/LATE(MPH) E 21 E 13 E 21
MIXING HGT(FT-AGL/MSL)5190 5230
TRANSPORT WND (MPH) E 17 E 17
VENT RATE (KT-FT) 77850 78450
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ017-182015-
NORTHERN HILLS-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 20 30
TEMP (24H TREND) 90 (+1) 71 (-3) 90
RH % (24H TREND) 59 (-1) 98 (+4) 58
WIND 20FT/EARLY(MPH) E 14 E 16 E 14
WIND 20FT/LATE(MPH) NE 18 E 11 NE 19
MIXING HGT(FT-AGL/MSL)6110 6260
TRANSPORT WND (MPH) E 14 E 14
VENT RATE (KT-FT) 73320 75120
DISPERSION 5 5
DSI 6 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ018-182015-
WEST COAST-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER PCLDY MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 20 20
TEMP (24H TREND) 92 (0) 72 (-2) 93
RH % (24H TREND) 57 (-3) 99 (+7) 55
WIND 20FT/EARLY(MPH) E 14 E 16 E 13
WIND 20FT/LATE(MPH) E 13 E 14 E 13
MIXING HGT(FT-AGL/MSL)4890 5310
TRANSPORT WND (MPH) E 9 E 10
VENT RATE (KT-FT) 39120 47790
DISPERSION 5 5
DSI 6 3 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ019-182015-
EASTERN INTERIOR-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 30 20
TEMP (24H TREND) 90 (+3) 72 (-4) 89
RH % (24H TREND) 56 (-5) 96 (+6) 57
WIND 20FT/EARLY(MPH) E 14 E 13 E 14
WIND 20FT/LATE(MPH) E 13 E 13 E 14
MIXING HGT(FT-AGL/MSL)6030 6060
TRANSPORT WND (MPH) E 16 E 16
VENT RATE (KT-FT) 84420 84840
DISPERSION 5 5
DSI 6 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ022-182015-
LUQUILLO MOUNTAIN RANGE-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 30 20
TEMP (24H TREND) 86 (+5) 69 (-5) 85
RH % (24H TREND) 64 (-8) 99 (+6) 64
WIND 20FT/EARLY(MPH) E 12 E 11 E 12
WIND 20FT/LATE(MPH) E 12 E 11 E 12
MIXING HGT(FT-AGL/MSL)5160 4290
TRANSPORT WND (MPH) E 18 E 17
VENT RATE (KT-FT) 82560 64350
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ023-182015-
CENTRAL MOUNTAIN RANGE-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 0 30
TEMP (24H TREND) 89 (+5) 67 (-4) 88
RH % (24H TREND) 59 (-5) 99 (+4) 58
WIND 20FT/EARLY(MPH) E 10 E 11 E 10
WIND 20FT/LATE(MPH) E 11 E 10 E 11
MIXING HGT(FT-AGL/MSL)7520 8300
TRANSPORT WND (MPH) E 9 E 9
VENT RATE (KT-FT) 60160 66400
DISPERSION 5 5
DSI 6 2 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ024-182015-
CAYEY MOUNTAIN RANGE-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR PCLDY MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 30 10
TEMP (24H TREND) 86 (+3) 71 (-2) 85
RH % (24H TREND) 63 (-4) 100 (+4) 63
WIND 20FT/EARLY(MPH) E 11 E 11 E 12
WIND 20FT/LATE(MPH) E 12 E 10 E 12
MIXING HGT(FT-AGL/MSL)5260 5050
TRANSPORT WND (MPH) E 18 E 18
VENT RATE (KT-FT) 84160 80800
DISPERSION 5 5
DSI 6 3 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ025-182015-
VIEQUES-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 30 20
TEMP (24H TREND) 90 (+2) 79 (0) 90
RH % (24H TREND) 59 (-2) 86 (-1) 58
WIND 20FT/EARLY(MPH) E 17 E 18 E 17
WIND 20FT/LATE(MPH) E 14 E 18 E 17
MIXING HGT(FT-AGL/MSL)3330 3450
TRANSPORT WND (MPH) E 22 E 22
VENT RATE (KT-FT) 63270 65550
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ026-182015-
CULEBRA-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 30 20
TEMP (24H TREND) 90 (+1) 78 (0) 90
RH % (24H TREND) 58 (-7) 89 (-5) 59
WIND 20FT/EARLY(MPH) E 17 E 18 E 17
WIND 20FT/LATE(MPH) E 14 E 19 E 16
MIXING HGT(FT-AGL/MSL)3340 3360
TRANSPORT WND (MPH) E 22 E 22
VENT RATE (KT-FT) 63460 63840
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ027-182015-
SOUTHWEST COASTAL PLAINS AND MONA ISLAND-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 10
TEMP (24H TREND) 92 (+1) 74 (-2) 92
RH % (24H TREND) 51 (-3) 88 (+5) 51
WIND 20FT/EARLY(MPH) E 17 G26 E 12 E 16 G24
WIND 20FT/LATE(MPH) SE 17 G25 E 12 E 17 G25
MIXING HGT(FT-AGL/MSL)5000 5620
TRANSPORT WND (MPH) E 18 E 17
VENT RATE (KT-FT) 80000 84300
DISPERSION 5 5
DSI 6 3 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ001-182015-
SAINT THOMAS AND SAINT JOHN-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 20 20
TEMP (24H TREND) 88 (+1) 74 (0) 87
RH % (24H TREND) 62 (-3) 96 (-1) 61
WIND 20FT/EARLY(MPH) E 17 E 18 E 18
WIND 20FT/LATE(MPH) E 14 E 19 E 17
MIXING HGT(FT-AGL/MSL)3800 3390
TRANSPORT WND (MPH) E 22 E 22
VENT RATE (KT-FT) 72200 64410
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ002-182015-
ST CROIX-
447 AM AST SAT JUL 18 2026
TODAY TONIGHT SUN
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 20 30
TEMP (24H TREND) 89 (0) 75 (-4) 90
RH % (24H TREND) 63 (+1) 95 (+7) 59
WIND 20FT/EARLY(MPH) E 18 E 17 E 18
WIND 20FT/LATE(MPH) E 16 E 19 E 16
MIXING HGT(FT-AGL/MSL)5260 4500
TRANSPORT WND (MPH) E 23 E 21
VENT RATE (KT-FT) 105200 81000
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
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